Lifting the Z question.

[HAWAIIZR-1]

Originally Posted by vilant

Well, I only plan to leave it up for a month, no more than two. I will be replacing the 2 front shocks. The rears are brand new. I guess I'll just use the 2 jacks to keep the rears supported and not worry about the fronts since they're getting changed.

Best wishes and you should be good to go. Mine was up way too long so I'm not surprised if that caused the damage.

[RyanChappel]

to Paul Workman;

I am not disagreeing with your experience of lifting your car. I know I saw it somewhere. The Previous Owner had a file of many,many reprints of letters to this forum, and communication with Marc Haibeck, and I read the entire file..can't remember if I saw the comments about lifting the cars there, or if it was in one of the service manuals...I will look at the manuals...I'm not just making it up.
Your analogy about hitting a pothole doesn't really fit though, if you think about it....

regards...RC

[scottfab]

Originally Posted by RyanChappel

to Paul Workman;

.... snip....
Your analogy about hitting a pothole doesn't really fit though, if you think about it....

regards...RC

I totally agree. College courses in "Strengths of Materials" teaches dynamic vs static loads. A pot hole is a short dynamic load. Lifting the whole front of the car via one corner and letting is stay that way for an extended period is a static load. I have no evidence this is bad for a ZR-1 but then..... Henry David Thoreau once said....
"Circumstantial evidence is occasionally very convincing, as when you find a trout in the milk."

[Paul Workman]

Ryan/scott...

The reference was to beaking the windshield if the car was jacked on one (front, I assume) corner. OK, you don't like the pothole analogy, but really now... Has anyone broken their windshield when putting a jack under one corner (to change a tire, or whatever)??? What's the difference between that and parking the car on uneven ground, for example?

I'm not suggesting jacking one corner and leaving it there indefinately, but my point is there is a lot of "circumstantial evidence" on (what seems to be) an endless variety of topics, and cracking the windshield as result of jacking on one corner really gets my eyes rolling...when I think about it. (How many jacks did GM provide with your ZR-1??)

These things aren't babies; not that unnecessary abuse is suggested at all. But, when you hear of "a trout in the milk" (using scottfab's illustration), one needs to step back and consider how it got there, and not assume it always was - is my point.

For what it's worth, I use a pair of jacks. But even then, after jacking all four corners and placing jack stands under the car, I've discovered the car to be cross-corner supported at times due to the floor being uneven by a tooth on the jack stands. I shim the jacks or adjust when that happens (OK, babying it I suppose). Maybe I'm wrong, but I'm just sayin (in reference to breaking the windshield only) "Oh, come on!!!"

And, back to the OP: I suppose you could remove the wheels if you're going to leave it jacked for an extended period. Seems like it couldn't hurt, and if others have had issues as result of leaving them on (even tho it may have been a "fish in the milk"), take 'em off.

Your mileage may vary...

P.

[scottfab]

The title to this thread is "Lifting the Z question".
While breaking the glass was mentioned
at no time can I see limiting the thread to "breaking glass".
I certainly did not. I only said "I would not lift one corner" at a time.
Other concerns that fit under the thread title are damage to shocks from prolonged weight hung off them and tires developing flat spots.

MY ONLY POINT in mentioning a trout in milk was the I cannot
prove lifting one corner is bad. It just seems overwhelmingly a BAD idea.
And that would be a 'period' at the end of "idea".

[pantera1683]

I dread every time I have to lift the Z for fear of a mishap. Any leads on where to purchase the pipe adapter?

[USAFPILOT]

got the size/ specs for the steel tube?

[Paul Workman]

A single datum does not a trend make, but mine hung for almost a year with no ill affects far as I could detect.



P.

[Z51JEFF]

Originally Posted by RyanChappel

Use caution picking up the Z. Getting the front end torqued on one side can cause the windshield to crack...

Ive owned 2 C4s,have had these cars up in the air from every corner and have never heard this before.

[Blue Flame Restorations]

Windshields are "float" installed, meaning that they are set in Butyl. As the car flexes, the windshield butyl acts as a pillow or sorts.

Think of your house window in a fixed frame vs a window set in frame of silicone. The windshield also has a laminate between the panes.

A cracked windshield from jacking the car on only one point would be an anomoly.